The Basics of Font Management
For operating systems to be able to use them, font files need to be stored in specific places. On a Windows PC, the principal font storehouse is the Windows/Fonts folder. From here, using a command from the File menu, you can install new fonts. You can also drag font files into this folder from other sources.
On the Mac, font files are stored in Fonts folders in each of the Library folders on the computer. The fonts in the Library found in the root folder are available to all users of that Mac. Fonts stored in the Libraries of individual users (found in the Users folder) are available only to those users. The fonts in the Library inside the System folder are used by the operating system and shouldn't be touched.
Certain application programs—generally those that come with their own collection of fonts—will store fonts in their own folders, where they alone can have access to them. This is a way of assuring that other applications can't use them, as they are generally licensed to the user only for use with the host application.
There is a breed of utility program called a font manager, whose job it is to help organize and manage the huge numbers of fonts that can come to populate your computer. Having too many fonts installed on your computer at the same time creates two main problems: First, it slows down your computer, which has to constantly keep track of all of those fonts. (Too many installed fonts may in fact cause your computer to freeze.) Second, it creates a Font menu that's too long to manage, requiring endless scrolling to find the font you're after. The main thing a font manager does is enable you to keep the number of fonts in your system at a minimum with very little effort.
The principal way it does this is by allowing you to install or remove fonts from active service individually or en masse at any time. You can build font sets to make this easier. You can have a certain set of fonts for a specific job, or a certain set of fonts that are associated with a particular program. Fonts can belong to two or more of these sets. Some font managers can automatically install whatever fonts are needed by a document that you open.
In addition, font management programs can help you organize your fonts in logical ways. Whereas an operating system would throw them in a single heap (or, worse, several hard-to-locate heaps), a font-management program can organize them according to any criteria you like: font format; historical style; text, display, or decorative use; or whatever else.
Mac OS X includes its own font-management program: Font Book, located in the Applications folder. Windows has no such utility, although there are several available from independent software developers.